timer: remove QEMU_TICKLESS_WORKAROUND

Qemu icount mode enabled, remove QEMU_TICKLESS_WORKAROUND.

Signed-off-by: Wentong Wu <wentong.wu@intel.com>

drivers/timer/Kconfig

@@ -305,20 +305,4 @@ config TICKLESS_CAPABLE
 	  z_clock_announce() (really, not to produce an interrupt at
 	  all) until the specified expiration.
 
-config QEMU_TICKLESS_WORKAROUND
-	bool "Disable tickless on qemu due to asynchrony bug"
-	depends on QEMU_TARGET && TICKLESS_KERNEL
-	help
-	  Qemu (without -icount) has trouble keeping time when the
-	  host process needs to timeshare.  The host OS will routinely
-	  schedule out a process at timescales equivalent to the guest
-	  tick rate.  With traditional ticks delivered regularly by
-	  the hardware, that's mostly OK as it looks like a late
-	  interrupt.  But in tickless mode, the driver needs some CPU
-	  in order to schedule the tick in the first place.  If that
-	  gets delayed across a tick boundary, time gets wonky.  This
-	  tunable is a hint to the driver to disable tickless
-	  accounting on qemu.  Use it only on tests that are known to
-	  have problems.
-
 endmenu

drivers/timer/arm_arch_timer.c

@@ -30,8 +30,7 @@ static void arm_arch_timer_compare_isr(void *arg)
 
 	last_cycle += delta_ticks * CYC_PER_TICK;
 
-	if (!IS_ENABLED(CONFIG_TICKLESS_KERNEL) ||
+	if (!IS_ENABLED(CONFIG_TICKLESS_KERNEL)) {
-	     IS_ENABLED(CONFIG_QEMU_TICKLESS_WORKAROUND)) {
 		u64_t next_cycle = last_cycle + CYC_PER_TICK;
 
 		if ((s64_t)(next_cycle - curr_cycle) < MIN_DELAY) {
@@ -62,7 +61,7 @@ void z_clock_set_timeout(s32_t ticks, bool idle)
 {
 	ARG_UNUSED(idle);
 
-#if defined(CONFIG_TICKLESS_KERNEL) && !defined(CONFIG_QEMU_TICKLESS_WORKAROUND)
+#if defined(CONFIG_TICKLESS_KERNEL)
 
 	if (idle) {
 		return;

drivers/timer/hpet.c

@@ -59,8 +59,7 @@ static void hpet_isr(void *arg)
 
 	last_count += dticks * cyc_per_tick;
 
-	if (!IS_ENABLED(CONFIG_TICKLESS_KERNEL) ||
+	if (!IS_ENABLED(CONFIG_TICKLESS_KERNEL)) {
-	    IS_ENABLED(CONFIG_QEMU_TICKLESS_WORKAROUND)) {
 		u32_t next = last_count + cyc_per_tick;
 
 		if ((s32_t)(next - now) < MIN_DELAY) {
@@ -128,7 +127,7 @@ void z_clock_set_timeout(s32_t ticks, bool idle)
 {
 	ARG_UNUSED(idle);
 
-#if defined(CONFIG_TICKLESS_KERNEL) && !defined(CONFIG_QEMU_TICKLESS_WORKAROUND)
+#if defined(CONFIG_TICKLESS_KERNEL)
 	if (ticks == K_TICKS_FOREVER && idle) {
 		GENERAL_CONF_REG &= ~GCONF_ENABLE;
 		return;

drivers/timer/riscv_machine_timer.c

@@ -14,8 +14,7 @@
 #define MAX_TICKS ((MAX_CYC - CYC_PER_TICK) / CYC_PER_TICK)
 #define MIN_DELAY 1000
 
-#define TICKLESS (IS_ENABLED(CONFIG_TICKLESS_KERNEL) &&		\
+#define TICKLESS IS_ENABLED(CONFIG_TICKLESS_KERNEL)
-		  !IS_ENABLED(CONFIG_QEMU_TICKLESS_WORKAROUND))
 
 static struct k_spinlock lock;
 static u64_t last_count;
@@ -93,7 +92,7 @@ void z_clock_set_timeout(s32_t ticks, bool idle)
 {
 	ARG_UNUSED(idle);
 
-#if defined(CONFIG_TICKLESS_KERNEL) && !defined(CONFIG_QEMU_TICKLESS_WORKAROUND)
+#if defined(CONFIG_TICKLESS_KERNEL)
 	/* RISCV has no idle handler yet, so if we try to spin on the
 	 * logic below to reset the comparator, we'll always bump it
 	 * forward to the "next tick" due to MIN_DELAY handling and

drivers/timer/xtensa_sys_timer.c

@@ -44,8 +44,7 @@ static void ccompare_isr(void *arg)
 
 	last_count += dticks * CYC_PER_TICK;
 
-	if (!IS_ENABLED(CONFIG_TICKLESS_KERNEL) ||
+	if (!IS_ENABLED(CONFIG_TICKLESS_KERNEL)) {
-	    IS_ENABLED(CONFIG_QEMU_TICKLESS_WORKAROUND)) {
 		u32_t next = last_count + CYC_PER_TICK;
 
 		if ((s32_t)(next - curr) < MIN_DELAY) {
@@ -70,7 +69,7 @@ void z_clock_set_timeout(s32_t ticks, bool idle)
 {
 	ARG_UNUSED(idle);
 
-#if defined(CONFIG_TICKLESS_KERNEL) && !defined(CONFIG_QEMU_TICKLESS_WORKAROUND)
+#if defined(CONFIG_TICKLESS_KERNEL)
 	ticks = ticks == K_TICKS_FOREVER ? MAX_TICKS : ticks;
 	ticks = MAX(MIN(ticks - 1, (s32_t)MAX_TICKS), 0);
 

samples/portability/cmsis_rtos_v2/timer_synchronization/prj.conf

@@ -9,6 +9,5 @@ CONFIG_THREAD_MONITOR=y
 CONFIG_INIT_STACKS=y
 CONFIG_POLL=y
 CONFIG_SCHED_SCALABLE=y
-CONFIG_QEMU_TICKLESS_WORKAROUND=y
 # The Zephyr CMSIS v2 emulation assumes that ticks are ms, currently
 CONFIG_SYS_CLOCK_TICKS_PER_SEC=1000

tests/kernel/common/prj.conf

@@ -2,7 +2,6 @@ CONFIG_ZTEST=y
 CONFIG_PRINTK=y
 CONFIG_LOG=y
 CONFIG_POLL=y
-CONFIG_QEMU_TICKLESS_WORKAROUND=y
 CONFIG_BOOT_DELAY=500
 CONFIG_IRQ_OFFLOAD=y
 CONFIG_TEST_USERSPACE=y

tests/kernel/sched/schedule_api/prj.conf

@@ -2,7 +2,6 @@ CONFIG_ZTEST=y
 CONFIG_IRQ_OFFLOAD=y
 CONFIG_NUM_PREEMPT_PRIORITIES=30
 #CONFIG_SCHED_SCALABLE=y
-CONFIG_QEMU_TICKLESS_WORKAROUND=y
 CONFIG_MAX_THREAD_BYTES=4
 CONFIG_TEST_USERSPACE=y
 CONFIG_MP_NUM_CPUS=1

tests/kernel/sched/schedule_api/prj_multiq.conf

@@ -2,6 +2,5 @@ CONFIG_ZTEST=y
 CONFIG_IRQ_OFFLOAD=y
 CONFIG_TEST_USERSPACE=y
 CONFIG_SCHED_MULTIQ=y
-CONFIG_QEMU_TICKLESS_WORKAROUND=y
 CONFIG_MAX_THREAD_BYTES=4
 CONFIG_MP_NUM_CPUS=1

tests/kernel/sleep/prj.conf

@@ -1,5 +1,4 @@
 CONFIG_IRQ_OFFLOAD=y
 CONFIG_ZTEST=y
-CONFIG_QEMU_TICKLESS_WORKAROUND=y
 CONFIG_TEST_USERSPACE=y
-CONFIG_MP_NUM_CPUS=1
+CONFIG_MP_NUM_CPUS=1

tests/kernel/timer/timer_api/prj.conf

@@ -1,5 +1,4 @@
 CONFIG_ZTEST=y
-CONFIG_QEMU_TICKLESS_WORKAROUND=y
 CONFIG_TEST_USERSPACE=y
 
 CONFIG_MP_NUM_CPUS=1

tests/kernel/workq/work_queue/prj.conf

@@ -1,5 +1,4 @@
 CONFIG_ZTEST=y
-CONFIG_QEMU_TICKLESS_WORKAROUND=y
 CONFIG_POLL=y
 
 # Not a single test case here is SMP-safe.  Save the cycles needed for

tests/net/socket/poll/prj.conf

@@ -20,7 +20,5 @@ CONFIG_MAIN_STACK_SIZE=2048
 
 CONFIG_ZTEST=y
 
-CONFIG_QEMU_TICKLESS_WORKAROUND=y
-
 CONFIG_NET_TEST=y
 CONFIG_NET_LOOPBACK=y

tests/net/socket/select/prj.conf

@@ -26,5 +26,3 @@ CONFIG_ZTEST=y
 # User mode requirements
 CONFIG_TEST_USERSPACE=y
 CONFIG_HEAP_MEM_POOL_SIZE=128
-
-CONFIG_QEMU_TICKLESS_WORKAROUND=y

tests/net/socket/socketpair/prj.conf

@@ -30,5 +30,3 @@ CONFIG_ZTEST=y
 # User mode requirements
 CONFIG_TEST_USERSPACE=y
 CONFIG_HEAP_MEM_POOL_SIZE=2048
-
-CONFIG_QEMU_TICKLESS_WORKAROUND=y